Antipsychotic plasma levels in the assessment of poor treatment response in schizophrenia

Antipsychotic Drugs: A Concise Review of History, Classification, Indications, Mechanism, Efficacy, Side Effects, Dosing, and Clinical Application

The introduction of the first antipsychotic drug, chlorpromazine, was a milestone for psychiatry. The authors review the history, classification, indications, mechanism, efficacy, side effects, dosing, drug initiation, switching, and other practical issues and questions related to antipsychotics. Classifications such as first-generation/typical versus second-generation/atypical antipsychotics are neither valid nor useful; these agents should be described according to the Neuroscience-based Nomenclature (NbN). Antipsychotic drugs are not specific for treating schizophrenia. They reduce psychosis regardless of the underlying diagnosis, and they go beyond nonspecific sedation. All currently available antipsychotic drugs are dopamine blockers or dopamine partial agonists. In schizophrenia, effect sizes for relapse prevention are larger than for acute treatment. A major unresolved problem is the implausible increase in placebo response in antipsychotic drug trials over the decades. Differences in side effects, which can be objectively measured, such as weight gain, are less equivocal than differences in rating-scale-measured (subjective) efficacy. The criteria for choosing among antipsychotics are mainly pragmatic and include factors such as available formulations, metabolism, half-life, efficacy, and side effects in previous illness episodes. Plasma levels help to detect nonadherence, and once-daily dosing at night (which is possible with many antipsychotics) and long-acting injectable formulations are useful when adherence is a problem. Dose-response curves for both acute treatment and relapse prevention follow a hyperbolic pattern, with maximally efficacious average dosages for schizophrenia of around 5 mg/day risperidone equivalents. Computer apps facilitating the choice between drugs are available. Future drug development should include pharmacogenetics and focus on drugs for specific aspects of psychosis.

Mood disorders and suicide: pilot study on postmortem toxicologic evidence and adherence to psychiatric therapy by determining blood levels of medications

Suicide is one of the leading causes of death today, and among all mental illness, mood disorders account for one of the main risk factors. It is well known and proven that suicides are very common among people undergoing treatment and prescribed psychiatric medication. So far, however, there have only been a few studies dealing with this particular phenomenon. For this reason, autopsy patients who died by suicide, suffered from a mood disorder, and were known to be taking psychiatric medication at the time of death were selected for this study. The blood and urine samples taken during the autopsy underwent toxicological analysis and the results were compared with the prescribed therapy. A total of 22 people were included in the study: 12 presenting with depression and 10 with bipolar disorder. The toxicological analysis revealed that only 6 cases (27%) showed a qualitative match with the prescribed medication. In 5 cases (22.7%) the medication was only partially complied with and in 11 cases (50%) it was not complied with at all. Furthermore, even when medication was present, the value was often below the therapeutic range. Overall, more than 70% of the test subjects adhered to their medication only partially or not at all. Since treatment adherence is considered as a key factor in reducing the risk of suicide, this inevitably raises relevant clinical and forensic questions. Against this background, prospective monitoring of post-mortem medication levels in suicidal individuals and synergistic collaboration between clinicians and forensic pathologists could help to evaluate the effectiveness of specific medical interventions, highlight existing critical problems and develop new approaches to suicide prevention.

Overcoming the barriers to identifying and managing treatment-resistant schizophrenia and to improving access to clozapine: A narrative review and recommendation for clinical practice

Clozapine is the only approved antipsychotic for treatment-resistant schizophrenia (TRS). Although a large body of evidence supports its efficacy and favorable risk-benefit ratio in individuals who have failed two or more antipsychotics, clozapine remains underused. However, variations in clozapine utilization across geographic and clinical settings suggest that it could be possible to improve its use. In this narrative review and expert opinion, we summarized information available in the literature on the mechanisms of action, effectiveness, and potential adverse events of clozapine. We identified barriers leading to discouragement in clozapine prescription internationally, and we proposed practical solutions to overcome each barrier. One of the main obstacles identified to the use of clozapine is the lack of appropriate training for physicians: we highlighted the need to develop specific professional programs to train clinicians, both practicing and in residency, on the relevance and efficacy of clozapine in TRS treatment, initiation, maintenance, and management of potential adverse events. This approach would facilitate physicians to identify eligible patients and offer clozapine as a treatment option in the early stage of the disease. We also noted that increasing awareness of the benefits of clozapine among healthcare professionals, people with TRS, and their caregivers can help promote the use of clozapine. Educational material, such as leaflets or videos, could be developed and distributed to achieve this goal. The information provided in this article may be useful to improve disease burden and support healthcare professionals, patients, and caregivers navigating the complex pathways to TRS management.

Rapid Metabolism Underlying Subtherapeutic Serum Levels of Atypical Antipsychotics Preceding Clozapine Treatment: A Retrospective Analysis of Real-World Data

INTRODUCTION

Adequate antipsychotic treatment intensity is required before diagnosing resistant schizophrenia and initiating clozapine treatment. We aimed to investigate potential rapid drug metabolism underlying low dose-adjusted serum concentration (CD) of non-clozapine atypical antipsychotics preceding clozapine treatment.

METHODS

Patients using non-clozapine, atypical antipsychotics (aripiprazole, risperidone, olanzapine, or quetiapine) within 1 year before starting clozapine were included in this study from a therapeutic drug monitoring service in Oslo, Norway, between 2005 and 2023. Patients were assigned into low CD (LCD) and normal CD (NCD) subgroups. Using a reference sample with 147,964 antipsychotic measurements, LCD was defined as CDs below the 25th percentile, while patients with NCD exhibited CDs between the 25th and 75th percentile of the respective reference measurements. Metabolic ratios, doses, and frequency of subtherapeutic levels of non-clozapine antipsychotics were compared between LCD and NCD groups.

RESULTS

Preceding clozapine treatment, 110 out of 272 included patients (40.4%) were identified with LCD. Compared with the NCD group, LCD patients exhibited higher metabolic ratios of olanzapine (1.5-fold; p < 0.001), quetiapine (3.0-fold; p < 0.001), and risperidone (6.0-fold; p < 0.001). Metabolic ratio differences were independent of smoking and CYP2D6 genotype for olanzapine (p = 0.008) and risperidone (p = 0.016), respectively. Despite higher doses of olanzapine (1.25-fold; p = 0.054) and quetiapine (1.6-fold; p = 0.001) in LCD versus NCD patients, faster metabolism among the former was accompanied by higher frequencies of subtherapeutic levels of olanzapine (3.3-fold; p = 0.044) and quetiapine (1.8-fold; p = 0.005).

CONCLUSION

LCD and associated rapid metabolism of non-clozapine antipsychotics is frequent before starting clozapine treatment. For olanzapine and quetiapine, this is associated with significantly increased risk of having subtherapeutic concentrations.

Exploring low clozapine C/D ratios, inverted clozapine-norclozapine ratios and undetectable concentrations as measures of non-adherence in clozapine patients: A literature review and a case series of 17 patients from 3 studies

BACKGROUND

Up to 1/2 of outpatients prescribed clozapine may be partially/fully non-adherent, based on therapeutic drug monitoring (TDM). Three indices for measuring partial/full non-adherence are proposed a: 1) clozapine concentration/dose (C/D) ratio which drops to half or more of what is expected in the patient; 2) clozapine/norclozapine ratio that becomes inverted; and 3) clozapine concentration that becomes non-detectable.

METHODS

These 3 proposed indices are based on a literature review and 17 cases of possible non-adherence from 3 samples: 1) an inpatient study in a Chinese hospital, 2) an inpatient randomized clinical trial in a United States hospital, and 3) and a Uruguayan outpatient study.

RESULTS

The first index of non-adherence is a clozapine C/D ratio which is less than half the ratio corresponding to the patient's specific ancestry group and sex-smoking subgroup. Knowing the minimum therapeutic dose of the patient based on repeated TDM makes it much easier to establish non-adherence. The second index is inverted clozapine/norclozapine ratios in the absence of alternative explanations. The third index is undetectable concentrations. By using half-lives, the chronology of the 3 indices of non-adherence was modeled in two patients: 1) the clozapine C/D ratio dropped to ≥1/2 of what is expected from the patient (around day 2); 2) the clozapine/norclozapine ratio became inverted (around day 3); and 3) the clozapine concentration became undetectable by the laboratory (around days 9-11).

CONCLUSION

Prospective studies should further explore these proposed clozapine indices in average patients, poor metabolizers (3 presented) and ultrarapid metabolizers (2 presented).

A proposal for reducing maximum target doses of drugs for psychosis: Reviewing dose-response literature

BACKGROUND

Presently, there is limited guidance on the maximal dosing of psychosis drugs that is based on effectiveness rather than safety or toxicity. Current maximum dosing recommendations may far exceed the necessary degree of dopamine D2 receptor blockade required to treat psychosis. This may lead to excess harm through cognitive impairment and side effects.

AIMS

This analysis aimed to establish guidance for prescribers by optimally dosing drugs for psychosis based on efficacy and benefit.

METHODS

We used data from two dose-response meta-analyses and reviewed seven of the most prescribed drugs for psychosis in the UK. Where data were not available, we used appropriate comparison techniques based on D2 receptor occupancy to extrapolate our recommendations.

RESULTS

We found that the likely threshold dose for achieving remission of psychotic symptoms was often significantly below the currently licensed dose for these drugs. We therefore recommend that clinicians are cautious about exceeding our recommended doses. Individual factors, however, should be accounted for. We outline potentially relevant factors including age, ethnicity, sex, smoking status and pharmacogenetics. Additionally, we recommend therapeutic drug monitoring as a tool to determine individual pharmacokinetic variation.

CONCLUSIONS

In summary, we propose a new set of maximum target doses for psychosis drugs based on efficacy. Further research through randomised controlled trials should be undertaken to evaluate the effect of reducing doses from current licensing maximums or from doses that are above our recommendations. However, dose reductions should be implemented in a manner that accounts for and reduces the effects of drug withdrawal.

Therapeutic Drug Level Monitoring of Antipsychotics at an Inpatient Psychiatric Hospital

BACKGROUND

The American Psychiatric Association guidelines for the treatment of patients with schizophrenia state that the utility of antipsychotic therapeutic drug monitoring (TDM) remains unclear, except for clozapine or assessing adherence. The aim of this study was to investigate the extent and impact of antipsychotic TDM in inpatient practice to improve its utilization.

METHODS

Patients with antipsychotic blood levels drawn between May 1, 2021 and January 31, 2023 were invited to consent for retrospective chart data analysis to determine the influence of antipsychotic blood levels on their treatment. Approximately 42% of patients consented. Data collected from the patients' electronic medical records included age, ethnicity, race, sex, diagnosis, comorbidities, adverse drug reactions, medications, doses and frequency, antipsychotics and levels, laboratory values, and treatment history. Comparisons were made between antipsychotic levels that were within and outside the therapeutic range and the status of antipsychotic regimen adjustments.

RESULTS

A total of 135 antipsychotic levels from 40 inpatients were analyzed. Approximately 48% of the levels were appropriately drawn, whereas 52% were inappropriately drawn. Clozapine had the highest TDM rate (59%) and the most common diagnoses were schizophrenia (45%) and schizoaffective disorder (32.5%). More levels were appropriately drawn for clozapine (47.3% versus 24.3%) than for risperidone (41% versus 46.2%). Appropriately drawn clozapine levels correlated with higher daily doses and levels at or above the therapeutic threshold of 350 ng/mL.

CONCLUSIONS

Most antipsychotic drug levels were inappropriately drawn, emphasizing the complexity and potential for errors in TDM. Although more patients were prescribed risperidone, clozapine had the highest TDM rate. Clinicians were more likely to keep antipsychotic regimens unchanged for appropriately drawn levels and adjust doses for inappropriately drawn levels.

Long-Acting Injectable Second-Generation Antipsychotics in Seriously Ill Patients with Schizophrenia: Doses, Plasma Levels, and Treatment Outcomes

This research studies the dose-plasma level (PL) relationship of second-generation antipsychotics, together with the treatment outcomes achieved, in seriously ill people with schizophrenia. An observational, prospective, one-year follow-up study was carried out with patients (N = 68) with severe schizophrenia treated with paliperidone three-month (PP3M) or aripiprazole one-month (ARIM). Participants were divided into standard-dose or high-dose groups. PLs were divided into "standard PL" and "high PL" (above the therapeutic reference range, TRR) groups. The dose/PL relationship, and severity, hospitalizations, tolerability, compliance, and their relationship with doses and PLs were evaluated. There was no clear linear relationship between ARIM or PP3M doses and the PLs achieved. In half of the subjects, standard doses reached PLs above the TRR. The improvements in clinical outcomes (decrease in clinical severity and relapses) were related to high PLs, without worse treatment tolerability or adherence. All participants remained in the study, regardless of dose or PL. Clinical severity and hospitalizations decreased significantly more in those patients with high PLs. Considering the non-linear dose-PL relationship of ARIM and PP3M in people with severe schizophrenia, PLs above the TRR are linked to better treatment outcomes, without worse tolerability. The need in a notable number of cases for high doses to reach those effective PLs is highlighted.

Evidence for Therapeutic Drug Monitoring of Atypical Antipsychotics

Second-generation antipsychotics (SGAs), also known as atypical antipsychotics, are a newer class of antipsychotic drugs used to treat schizophrenia, bipolar disorder, and related psychiatric conditions. The plasma concentration of antipsychotic drugs is a valid measure of the drug at its primary target structure in the brain, and therefore determines the efficacy and safety of these drugs. However, despite the well-known high variability in pharmacokinetics of these substances, psychiatric medication is usually administered in uniform dosage schedules. Therapeutic drug monitoring (TDM), as the specific method that can help personalised medicine in dose adjustment according to the characteristics of the individual patient, minimizing the risk of toxicity, monitoring adherence, and increasing cost-effectiveness in the treatment, thus seems to be an elegant tool to solve this problem. Non-response to therapeutic doses, uncertain adherence to medication, suboptimal tolerability, or pharmacokinetic drug-drug interactions are typical indications for TDM of SGAs. This review aims to summarize an overview of the current knowledge and evidence of the possibilities to tailor the dosage of selected SGAs using TDM, including the necessary pharmacokinetic parameters for personalised pharmacotherapy.

Plasmatic Levels and Response to Variable Doses of Monthly Aripiprazole and Three-Month Paliperidone in Patients with Severe Schizophrenia. Treatment Adherence, Effectiveness, Tolerability, and Safety

Introduction

There is a need when optimizing antipsychotic treatment to know the plasmatic levels (PLs) achieved with the different doses and their relationship with effectiveness and toxicity, especially in patients with poor clinical progress. This study investigates the dose-PL-response relationship of monthly aripiprazole (AOM) and three-month paliperidone (PP3M).

Methods

Observational, 52-week prospective study of patients with severe schizophrenia (CGI-S ≥ 5) treated with PP3M or AOM for at least one year before their inclusion in the study (N=68). Dose-PL relationship was determined. Subjects were included in standard-dose and high-dose (above labeled) and standard/therapeutic range-PLs and high-PLs (above range) groups. Treatment adherence, effectiveness (hospitalizations, severity), tolerability and safety were assessed. PLs and clinical response were evaluated.

Results

No clear linear relationship was found between doses and PLs. In a considerable number of cases, standard doses achieved PLs above the therapeutic range. A significant clinical improvement was related to high PLs, without less safety, tolerability, or treatment compliance being involved. Clinical severity decreased more frequently in patients who received high doses and reached high PLs. Hospital admissions decreased significantly in those patients with high PLs.

Conclusion

Taking into account the absence of a linear relationship between doses and PLs, the effectiveness in people with severe schizophrenia of AOM and PP3M depends on reaching high PLs, achieved with high doses, but also with standard doses in some cases, without leading to worse treatment tolerability, safety, or adherence.

Effect of anticholinergic burden on brain activity during Working Memory and real-world functioning in patients with schizophrenia

Cognitive impairment has been associated with poor real-world functioning in patients with Schizophrenia. Previous studies have shown that pharmacological treatment with anticholinergic properties may contribute to cognitive impairment in Schizophrenia. We investigated the effect of the anticholinergic burden (ACB) on brain activity, cognition, and real-world functioning in Schizophrenia. We hypothesized that greater ACB would be associated with altered brain activity along with poorer cognitive performance and lower real-world functioning. A sample of 100 patients with a diagnosis of schizophrenia or schizoaffective disorder was recruited in the naturalistic multicenter study of the Italian Network for Research on Psychoses (NIRP) across 7 centres. For each participant, ACB was evaluated using the Anticholinergic Cognitive Burden scale. The association of ACB with brain function was assessed using BOLD fMRI during the N-Back Working Memory (WM) task in a nested cohort (N = 31). Real-world functioning was assessed using the Specific Level of Functioning (SLOF) scale. Patients with high ACB scores (≥3) showed lower brain activity in the WM frontoparietal network (TFCE corrected alpha <0.05) and poorer cognitive performance (p = 0.05) than patients with low ACB scores (<3). Both effects were unaffected by demographic characteristics, clinical severity, and antipsychotic dosage. Moreover, patients with high ACB showed poorer real-world functioning than patients with lower ACB (p = 0.03). Our results suggest that ACB in Schizophrenia is associated with impaired WM and abnormal underlying brain function along with reduced real-world functioning. Clinical practice should consider the potential adverse cognitive effects of ACB in the treatment decision-making process.

Comparing the pharmacology and pharmacokinetics of antipsychotics: Choosing an antipsychotic and dosing a long-acting injectable

In this paper, we will discuss the pharmacologic properties of antipsychotics, including those that are the same in structure and those that differentiate one from another. We will bring to you how differential pharmacologic properties can explain differential efficacy and differential tolerability. We will review how to use plasma drug levels and long-acting injectables to enhance compliance early in the illness, and to manage both forms of treatment resistance (pharmacokinetic and pharmacodynamic failures). Through inadequate pharmacokinetic processes (poor absorption, rapid metabolism, enzymatic polymorphisms, etc.), antipsychotic plasma levels do not reach sufficient concentration. Pharmacodynamic treatment failure (receptor binding and sensitivity, post-receptor effects, etc.) is the inability to provide a significant effect on psychotic symptoms despite therapeutic plasma levels. Long-Acting Injectable (LAI) antipsychotics employ technology that can provide a useful treatment tool in the armamentarium of a modern psychopharmacologist. The pharmacologic properties of antipsychotics differentiate one from another and can help explain differences in efficacy and tolerability. Utilizing plasma drug levels can enhance understanding of treatment failures and lead to specific patient management strategies for best outcomes. This kind of personalized approach to antipsychotic dosage would mean a big shift in the treatment of psychiatric patients.

Aripiprazole Plasma Concentrations Delivered from Two 2-Month Long-Acting Injectable Formulations: An Indirect Comparison

Aripiprazole 2-month ready-to-use 960 mg (Ari 2MRTU 960) is a novel long-acting injectable (LAI) formulation of aripiprazole monohydrate for administration once every 2 months, developed for the treatment of schizophrenia or maintenance monotherapy treatment of bipolar I disorder in adults (indication will vary by country). Aripiprazole lauroxil 1064 mg (AL 1064) is an LAI formulation of aripiprazole lauroxil, an aripiprazole prodrug, for administration once every 2 months, indicated for the treatment of schizophrenia in adults. This analysis provides an indirect comparison of aripiprazole plasma concentrations following multiple doses of either formulation. Clinical trial data were used to determine average steady-state aripiprazole plasma concentration (Cavg,ss), maximum aripiprazole plasma concentration (Cmax), and other pharmacokinetic parameters of either formulation following four administrations (96 patients received Ari 2MRTU 960; 28 patients received AL 1064). All pharmacokinetic parameters were considered in the context of a minimum aripiprazole therapeutic concentration (Cmin) of ≥95 ng/mL. An exposure-response analysis using data from two Phase III trials of aripiprazole once-monthly (an aripiprazole monohydrate LAI, administered monthly), showed that patients with a Cmin ≥95 ng/mL are 4.41 times less likely to relapse than patients with a Cmin <95 ng/mL. A similar analysis has not been performed for AL 1064. However, consensus guidelines for therapeutic drug monitoring recommend a range of 100-350 ng/mL for aripiprazole. Following four administrations, mean (standard deviation [SD]) Cavg,ss over the 2-month dosing interval was 263 (133) ng/mL for Ari 2MRTU 960 and 140.7 (57.3) ng/mL for AL 1064. Mean (SD) Cmax during the fourth dosing interval was 342 (157) ng/mL for Ari 2MRTU 960 and 188.8 (79.8) ng/mL for AL 1064. This indirect comparison showed that, following four administrations, Ari 2MRTU 960 and AL 1064 delivered mean aripiprazole plasma concentrations that remained above the minimum therapeutic concentration of aripiprazole over the 2-month dosing interval.

Computerized cognitive and social cognition training in schizophrenia for impulsive aggression

BACKGROUND

Schizophrenia is associated with an elevated risk for impulsive aggression for which there are few psychosocial treatment options. Neurocognitive and social cognitive deficits have been associated with aggression with social cognitive deficits seemingly a more proximal contributor. The current study examined the effects of combining cognitive and social cognition treatment on impulsive aggression among inpatients with chronic schizophrenia and schizoaffective disorder and a history of aggression compared to cognitive remediation treatment alone.

METHODS

The two-center study randomized 130 participants to receive 36 sessions of either a combination of cognitive remediation and social cognition treatment or cognitive remediation plus a computer-based control. Participants had at least one aggressive incident within the past year or a Life History of Aggression (LHA) score of 5 or more. Participants completed measures of neurocognition, social cognition, symptom severity, and aggression at baseline and endpoint.

RESULTS

Study participants were mostly male (84.5 %), had a mean age 34.9 years, and 11.5 years of education. Both Cognitive Remediation Training (CRT) plus Social Cognition Training (SCT) and CRT plus control groups were associated with significant reductions in aggression measures with no group differences except on a block of the Taylor Aggression Paradigm (TAP), a behavioral task of aggression which favored the CRT plus SCT group. Both groups showed significant improvements in neurocognition and social cognition measures with CRT plus SCT being associated with greater improvements.

CONCLUSION

CRT proved to be an effective non-pharmacological treatment in reducing impulsive aggression in schizophrenia inpatient participants with a history of aggressive episodes. The addition of social cognitive training did not enhance this anti-aggression treatment effect but did augment the CRT effect on cognitive functions, on emotion recognition and on mentalizing capacity of our participants.

Early Non-Response to Antipsychotic Treatment in Schizophrenia: A Systematic Review and Meta-Analysis of Evidence-Based Management Options

BACKGROUND

Early non-response is a well-established prognostic marker but evidence-based and consistent recommendations to manage it are limited. The aim of this systematic review and meta-analysis was to generate evidence-based strategies for the management of schizophrenia patients with early non-response to 2 weeks of antipsychotic treatment.

METHODS

We conducted a systematic review and meta-analysis of randomized trials comparing antipsychotic dose escalation, switch, augmentation and continuation in individuals with study-defined early antipsychotic treatment non-response. Eligibility criteria were (1) clinical trials of primary psychosis treating for at least 2 weeks with antipsychotic monotherapy with study-defined operationalized criteria for early non-response; and (2) randomization to at least two of the following treatment strategies: dose escalation, switch, augmentation, or treatment continuation. Information sources were Pubmed, PsycINFO, and EMBASE, and risk of bias was assessed using Jadad scores. Results were synthesized using random-effects meta-analysis, comparing each intervention with treatment continuation for total symptom change as the primary outcome, generating standardized mean differences (SMDs) and 95% confidence intervals (CIs). Studies meeting the selection criteria but providing insufficient data for a meta-analysis were presented separately.

RESULTS

We screened 454 records by 1 August 2022, of which 12 individual datasets met the inclusion criteria, representing 947 research participants. Of those studies, five provided data to include in the meta-analysis (four with early non-response at 2 weeks, one at 3 weeks). Early non-response was defined within a timeline of 2 weeks in eight datasets, with the remaining datasets ranging between 3 and 4 weeks. The rates of early non-response ranged between 72.0 and 24.1%, and the endpoint ranged within 4-24 weeks post randomization. Quality was good (i.e., Jadad score of ≥3) in 8 of the 12 datasets. Overall, three studies compared antipsychotic switch versus continuation and two compared antipsychotic switch versus augmentation, in both cases without significant pooled between-group differences for total symptom severity (n = 149, SMD 0.18, 95% CI -0.14 to 0.5). Individually, two relatively large studies for antipsychotic switch versus continuation found small advantages for switching antipsychotics for total symptom severity (n = 149, SMD -0.49, 95% CI -1.05 to -0.06). One relatively large study found an advantage for dose escalation, although this finding has not been replicated and was not included in the meta-analysis. None of the alternatives included antipsychotic switch to clozapine.

CONCLUSIONS

Despite robust accuracy of early antipsychotic non-response predicting ultimate response, the evidence for treatment strategies that should be used for early non-response after 2-3 weeks is limited. While meta-analytic findings were non-significant, some individual studies suggest advantages of antipsychotic switch or dose escalation. Therefore, any conclusions should be interpreted carefully, given the insufficient high-quality evidence.

Second to none: rationale, timing, and clinical management of clozapine use in schizophrenia

Despite its enduring relevance as the single most effective and important evidence-based treatment for schizophrenia, underutilization of clozapine remains considerable. To a substantial degree, this is attributable to a reluctance of psychiatrists to offer clozapine due to its relatively large side-effect burden and the complexity of its use. This underscores the necessity for continued education regarding both the vital nature and the intricacies of clozapine treatment. This narrative review summarizes all clinically relevant areas of evidence, which support clozapine's wide-ranging superior efficacy - for treatment-resistant schizophrenia (TRS) and beyond - and make its safe use eminently feasible. Converging evidence indicates that TRS constitutes a distinct albeit heterogeneous subgroup of schizophrenias primarily responsive to clozapine. Most importantly, the predominantly early onset of treatment resistance and the considerable decline in response rates associated with its delayed initiation make clozapine an essential treatment option throughout the course of illness, beginning with the first psychotic episode. To maximize patients' benefits, systematic early recognition efforts based on stringent use of TRS criteria, a timely offer of clozapine, thorough side-effect screening and management as well as consistent use of therapeutic drug monitoring and established augmentation strategies for suboptimal responders are crucial. To minimize permanent all-cause discontinuation, re-challenges after neutropenia or myocarditis should be considered. Owing to clozapine's unique efficacy, comorbid conditions including substance use and most somatic disorders should not dissuade but rather encourage clinicians to consider clozapine. Moreover, treatment decisions need to be informed by the late onset of clozapine's full effects, which for reduced suicidality and mortality rates may not even be readily apparent. Overall, the singular extent of its efficacy combined with the high level of patient satisfaction continues to distinguish clozapine from all other available antipsychotics.

Altered Patterns of Brain Glucose Metabolism Involve More Extensive and Discrete Cortical Areas in Treatment-resistant Schizophrenia Patients Compared to Responder Patients and Controls: Results From a Head-to-Head 2-[18F]-FDG-PET Study

BACKGROUND AND HYPOTHESIS

Treatment resistant schizophrenia (TRS) affects almost 30% of patients with schizophrenia and has been considered a different phenotype of the disease. In vivo characterization of brain metabolic patterns associated with treatment response could contribute to elucidate the neurobiological underpinnings of TRS. Here, we used 2-[18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) to provide the first head-to-head comparative analysis of cerebral glucose metabolism in TRS patients compared to schizophrenia responder patients (nTRS), and controls. Additionally, we investigated, for the first time, the differences between clozapine responders (Clz-R) and non-responders (Clz-nR).

STUDY DESIGN

53 participants underwent FDG-PET studies (41 patients and 12 controls). Response to conventional antipsychotics and to clozapine was evaluated using a standardized prospective procedure based on PANSS score changes. Maps of relative brain glucose metabolism were processed for voxel-based analysis using Statistical Parametric Mapping software.

STUDY RESULTS

Restricted areas of significant bilateral relative hypometabolism in the superior frontal gyrus characterized TRS compared to nTRS. Moreover, reduced parietal and frontal metabolism was associated with high PANSS disorganization factor scores in TRS (P < .001 voxel level uncorrected, P < .05 cluster level FWE-corrected). Only TRS compared to controls showed significant bilateral prefrontal relative hypometabolism, more extensive in CLZ-nR than in CLZ-R (P < .05 voxel level FWE-corrected). Relative significant hypermetabolism was observed in the temporo-occipital regions in TRS compared to nTRS and controls.

CONCLUSIONS

These data indicate that, in TRS patients, altered metabolism involved discrete brain regions not found affected in nTRS, possibly indicating a more severe disrupted functional brain network associated with disorganization symptoms.

Pharmacokinetics and pharmacogenomics of clozapine in an ancestrally diverse sample: a longitudinal analysis and genome-wide association study using UK clinical monitoring data

BACKGROUND

The antipsychotic, clozapine, is the only licensed drug against the treatment-resistant symptoms that affect 20-30% of people with schizophrenia. Clozapine is markedly underprescribed, partly because of concerns about its narrow therapeutic range and adverse drug reaction profile. Both concerns are linked to drug metabolism, which varies across populations globally and is partly genetically determined. Our study aimed to use a cross-ancestry genome-wide association study (GWAS) design to investigate variations in clozapine metabolism within and between genetically inferred ancestral backgrounds, to discover genomic associations to clozapine plasma concentrations, and to assess the effects of pharmacogenomic predictors across different ancestries.

METHODS

In this GWAS, we analysed data from the UK Zaponex Treatment Access System clozapine monitoring service as part of the CLOZUK study. We included all available individuals with clozapine pharmacokinetic assays requested by their clinicians. We excluded people younger than 18 years, or whose records contained clerical errors, or with blood drawn 6-24 h after dose, a clozapine or norclozapine concentration less than 50 ng/mL, a clozapine concentration of more than 2000 ng/mL, a clozapine-to-norclozapine ratio outside of the 0·5-3·0 interval, or a clozapine dose of more than 900 mg/day. Using genomic information, we identified five biogeographical ancestries: European, sub-Saharan African, north African, southwest Asian, and east Asian. We did pharmacokinetic modelling, a GWAS, and a polygenic risk score association analysis using longitudinal regression analysis with three primary outcome variables: two metabolite plasma concentrations (clozapine and norclozapine) and the clozapine-to-norclozapine ratio.

FINDINGS

19 096 pharmacokinetic assays were available for 4760 individuals in the CLOZUK study. After data quality control, 4495 individuals (3268 [72·7%] male and 1227 [27·3%] female; mean age 42·19 years [range 18-85]) linked to 16 068 assays were included in this study. We found a faster average clozapine metabolism in people of sub-Saharan African ancestry than in those of European ancestry. By contrast, individuals with east Asian or southwest Asian ancestry were more likely to be slow clozapine metabolisers than those with European ancestry. Eight pharmacogenomic loci were identified in the GWAS, seven with significant effects in non-European groups. Polygenic scores generated from these loci were associated with clozapine outcome variables in the whole sample and within individual ancestries; the maximum variance explained was 7·26% for the metabolic ratio.

INTERPRETATION

Longitudinal cross-ancestry GWAS can discover pharmacogenomic markers of clozapine metabolism that, individually or as polygenic scores, have consistent effects across ancestries. Our findings suggest that ancestral differences in clozapine metabolism could be considered for optimising clozapine prescription protocols for diverse populations.

FUNDING

UK Academy of Medical Sciences, UK Medical Research Council, and European Commission.

The Use of Second-Generation Antipsychotics in Patients with Severe Schizophrenia in the Real World: The Role of the Route of Administration and Dosage-A 5-Year Follow-Up

To assess the impact of the route of administration and doses of second-generation antipsychotics (SGAs) on treatment adherence, hospital admissions, and suicidal behaviour in patients with severe schizophrenia (Clinical Global Impression−Severity−CGI-S ≥ 5), we implemented an observational 5-year follow-up study. A total of 37.5% of the patients on oral antipsychotics (Aps) and 11.5% of those on long-acting injectables (LAIs) abandoned the treatment (p < 0.001). There were no differences in treatment discontinuation between the LAI-AP standard and high-dose groups. A total of 28.1% of the patients on oral Aps had at least one hospitalisation, as well as 13.1% of patients on LAIs (p < 0.001). There were fewer hospitalisations of patients on LAIs in the high-dose group (p < 0.05). Suicide attempts were recorded for 18% of patients on oral Aps but only for 4.6% of patients on LAIs (p < 0.001). No differences were found between the dosage groups on LAIs. Tolerability was good for all Aps and somewhat better for LAIs than oral Aps in terms of side effects (p < 0.05). There were no differences between the standard and high-dose groups. More patients discontinued treatment due to side effects in the oral AP group (p < 0.01). LAI SGA treatment was more effective than oral AP in terms of adherence and treatment outcomes for managing people with severe schizophrenia. Moreover, significant improvements were found that favour high-dose LAI SGA treatment for some of these patients. This study highlights the need to consider LAI antipsychotics and high-dose strategies for patients with severe schizophrenia.

Current Status of Therapeutic Drug Monitoring in Mental Health Treatment: A Review

Therapeutic drug monitoring (TDM) receives growing interest in different psychiatric clinical settings (emergency, inpatient, and outpatient services). Despite its usefulness, TDM remains underemployed in mental health. This is partly due to the need for evidence about the relationship between drug serum concentration and efficacy and tolerability, both in the general population and even more in subpopulations with atypical pharmacokinetics. This work aims at reviewing the scientific literature published after 2017, when the most recent guidelines about the use of TDM in mental health were written. We found 164 pertinent records that we included in the review. Some promising studies highlighted the possibility of correlating early drug serum concentration and clinical efficacy and safety, especially for antipsychotics, potentially enabling clinicians to make decisions on early laboratory findings and not proceeding by trial and error. About populations with pharmacokinetic peculiarities, the latest studies confirmed very common alterations in drug blood levels in pregnant women, generally with a progressive decrease over pregnancy and a very relevant dose-adjusted concentration increase in the elderly. For adolescents also, several drugs result in having different dose-related concentration values compared to adults. These findings stress the recommendation to use TDM in these populations to ensure a safe and effective treatment. Moreover, the integration of TDM with pharmacogenetic analyses may allow clinicians to adopt precise treatments, addressing therapy on an individual pharmacometabolic basis. Mini-invasive TDM procedures that may be easily performed at home or in a point-of-care are very promising and may represent a turning point toward an extensive real-world TDM application. Although the highlighted recent evidence, research efforts have to be carried on: further studies, especially prospective and fixed-dose, are needed to replicate present findings and provide clearer knowledge on relationships between dose, serum concentration, and efficacy/safety.

Therapeutic Drug Monitoring of Long-Acting Injectable Antipsychotics as a Predictor of Relapse in Schizophrenia Spectrum Disorders: A 1-Year Pilot Study

BACKGROUND

Long-acting injectable antipsychotics (LAIs) have been shown to reduce acute episodes of schizophrenia spectrum disorders (SSDs). However, breakthrough relapses are frequent, possibly because of underdosing in clinical practice. In this framework, the advantages of therapeutic drug monitoring (TDM) may be overlooked. This study explored the association of low steady-state LAI levels with a higher risk of relapse in SSDs, despite the use of a licensed posology.

METHODS

Forty-eight clinically stable outpatients with SSD underwent LAI-TDM using liquid chromatography-mass spectrometry for routine observational purposes. Baseline anamnestic, pharmacological, and psychometric evaluations compared subjects with "under-range" versus "in-range" LAI serum levels; between-group comparisons for different LAI treatments were also performed. A binary logistic regression explored which baseline factors (age, sex, previous hospitalizations, psychopathology, specific LAI treatment, and underrange serum levels) predicted relapse during the next 12 months.

RESULTS

Baseline comparisons did not show significant between-group differences, except for a higher percentage of underrange values in individuals receiving olanzapine pamoate. A total of 10 patients (20.8%) relapsed during the follow-up; only underrange LAI levels predicted the event (odds ratio 0.03, 95% confidence interval 0.01-0.36; P = 0.005).

CONCLUSIONS

Even if relapse remains as a multifactorial event, LAI-TDM may identify subjects at risk for this negative outcome, thus optimizing antipsychotic maintenance treatment in the context of precision medicine. The finding of underrange LAI plasma levels in real-world practice should prompt adequate monitoring of clinically stable outpatients to identify the early signs of psychopathological deterioration.

Heterogeneity in treatment outcomes and incomplete recovery in first episode psychosis: does one size fit all?

The heterogeneity in recovery outcomes for individuals with First Episode Psychosis (FEP) calls for a strong evidence base to inform practice at an individual level. Between 19-89% of young people with FEP have an incomplete recovery despite gold-standard evidence-based treatments, suggesting current service models, which adopt a 'one-size fits all' approach, may not be addressing the needs of many young people with psychosis. The lack of consistent terminology to define key concepts such as recovery and treatment resistance, the multidimensional nature of these concepts, and common comorbid symptoms are some of the challenges faced by the field in delineating heterogeneity in recovery outcomes. The lack of robust markers for incomplete recovery also results in potential delay in delivering prompt, and effective treatments to individuals at greatest risk. There is a clear need to adopt a stratified approach to care where interventions are targeted at subgroups of patients, and ultimately at the individual level. Novel machine learning, using large, representative data from a range of modalities, may aid in the parsing of heterogeneity, and provide greater precision and sophistication in identifying those on a pathway to incomplete recovery.

Efficacy and safety of Lu AF35700 in treatment-resistant schizophrenia: A randomized, active-controlled trial with open-label extension

INTRODUCTION

Treatment resistance constitutes the highest burden of disease within schizophrenia. We hypothesized that the synergistic activity of Lu AF35700 at dopamine D1 and D2 receptors might provide superior antipsychotic effects versus first-line antipsychotic therapy in patients with treatment resistant schizophrenia (TRS), with a benign tolerability profile.

METHODS

This was a randomized, double-blind, active-controlled clinical trial (NCT02717195) followed by a one year open-label safety extension (NCT02892422). Following prospective confirmation of treatment resistance, patients were randomized (1:1:1) to 10 weeks double-blind treatment with Lu AF35700 10 mg or 20 mg, or active comparator (risperidone or olanzapine).

RESULTS

1628 patients were screened for TRS, of which 1092 entered the prospective confirmation period. Of these, 697 were randomized (Lu AF35700 10 mg n = 235, 20 mg n = 232, comparator n = 230) and 395 discontinued before randomization, including 264 (24 %) who responded to treatment. 586 patients completed the double-blind phase, of which 524 entered the open-label extension and 318 completed 1-year of open-label treatment. At the end of the double-blind phase, the mean ± SE change in positive and negative syndrome scale (PANSS) total score was -10.1 ± 0.96 for Lu AF35700 10 mg, -8.22 ± 0.98 for Lu AF35700 20 mg, and - 9.90 ± 0.97 for the comparator group. Treatment differences [95 % CI] versus comparator treatment were non-significant (-0.12 [-2.37; 2.13] and 1.67 [-0.59; 3.94], respectively). The most common adverse events with Lu AF35700 were increased weight and headache. Prolactin values decreased by ≥50 % in both sexes treated with Lu AF35700.

CONCLUSIONS

Despite evidence of antipsychotic efficacy, treatment with Lu AF35700 failed to differentiate from conventional antipsychotic treatment for patients with TRS.

Comorbidities and the right dose: antipsychotics

INTRODUCTION

The effects of antipsychotic drugs are dose-dependent, which is particularly true for their efficacy, each antipsychotic having a specific dose-response curve. This may justify individualizing doses for these agents.

AREAS COVERED

We review the pharmacokinetic profiles of seven oral antipsychotics: haloperidol, risperidone, olanzapine, clozapine, quetiapine, ziprasidone, and aripiprazole. Their main indications are psychotic and affective disorders. They are prescribed in a very large population which may have comorbidities. Hence, we analyze the impact of the latter on the pharmacokinetic profiles of these antipsychotics, focusing on renal and hepatic impairment. Reviews and clinical trials were discussed based on a systematic literature search (PubMed) ranging from 1995 to 2022.

EXPERT OPINION

Factors liable to impact antipsychotic dosage are numerous and their subsequent effects often hard to predict, due to multi-level interactions and compensatory phenomena. In clinical practice, physicians must be aware of these potential effects, but base their decisions on monitoring antipsychotic plasma levels.

A polygenic score indexing a DRD2-related co-expression network is associated with striatal dopamine function

The D2 dopamine receptor (D2R) is the primary site of the therapeutic action of antipsychotics and is involved in essential brain functions relevant to schizophrenia, such as attention, memory, motivation, and emotion processing. Moreover, the gene coding for D2R (DRD2) has been associated with schizophrenia at a genome-wide level. Recent studies have shown that a polygenic co-expression index (PCI) predicting the brain-specific expression of a network of genes co-expressed with DRD2 was associated with response to antipsychotics, brain function during working memory in patients with schizophrenia, and with the modulation of prefrontal cortex activity after pharmacological stimulation of D2 receptors. We aimed to investigate the relationship between the DRD2 gene network and in vivo striatal dopaminergic function, which is a phenotype robustly associated with psychosis and schizophrenia. To this aim, a sample of 92 healthy subjects underwent 18F-DOPA PET and was genotyped for genetic variations indexing the co-expression of the DRD2-related genetic network in order to calculate the PCI for each subject. The PCI was significantly associated with whole striatal dopamine synthesis capacity (p = 0.038). Exploratory analyses on the striatal subdivisions revealed a numerically larger effect size of the PCI on dopamine function for the associative striatum, although this was not significantly different than effects in other sub-divisions. These results are in line with a possible relationship between the DRD2-related co-expression network and schizophrenia and extend it by identifying a potential mechanism involving the regulation of dopamine synthesis. Future studies are needed to clarify the molecular mechanisms implicated in this relationship.

Aripiprazole for the treatment of schizophrenia: Recommendations of a panel of Spanish experts on its use in clinical practice

OBJECTIVES

Aripiprazole is an antipsychotic with a partial agonism of dopamine D₂ and D₃ receptors. This differential mechanism implies a rigorous appraisal of the appropriate therapeutic strategies in certain situations. To answer currently unsolved clinical questions about the use of oral and long-acting injectable (LAI) aripiprazole, we present here an expert consensus from 12 Spanish psychiatrists and a pharmacologist with extensive experience in the use of this antipsychotic.

METHODS

Through one face-to-face session and online collaboration, we reached consensus and established practical recommendations based on scientific evidence and clinical experience. We classified the available scientific literature according to SIGN system and attributed a level of evidence to each reviewed article.

RESULTS

The recommendations were divided according to (i) chronological dimension (based on previous treatments, including patients naïve or not to antipsychotic treatment and maintenance regimen), and (ii) dimension related to therapeutic options, comprising switches to aripiprazole and the most used combinations with this antipsychotic.

CONCLUSIONS

We recommend considering aripiprazole as first treatment option in the early stages of schizophrenia and in patients with affective symptoms and contemplating a switch to aripiprazole LAI in all candidate patients. Importantly, switches from other antipsychotics should consider previous antipsychotic history and exposure to aripiprazole. KEYPOINTSAripiprazole can be considered as first treatment option in early stages of schizophrenia and in patients with significant affective symptoms.Aripiprazole LAI shows better adherence than oral aripiprazole and could be considered in all candidate patients.Before switching to aripiprazole, detailed information about previous antipsychotic history should be gathered.Switch to aripiprazole should be managed differently for aripiprazole naïve and non-naïve patients.Rigorous and controlled studies on antipsychotics in real clinical practice should be carried out.

An Integrated Pharmacokinetic-Pharmacodynamic-Pharmacoeconomic Modeling Method to Evaluate Treatments for Adults with Schizophrenia

INTRODUCTION

Schizophrenia is a chronic mental disorder that worsens with each relapse. Long-acting injectable (LAI) antipsychotics may prevent the exacerbation of symptoms and occurrence of relapses through improved continuity of care. Different dose regimens are available for the LAIs aripiprazole monohydrate (AM) and aripiprazole lauroxil (AL), but their cost effectiveness is unclear.

OBJECTIVES

The study aim was to compare costs and effects (relapses) of the different aripiprazole LAI dose regimens to inform clinical and US payer decisions.

METHODS

A state-transition model calculated the outcomes of eight LAI dose regimens based on their relapse rates. As effectiveness data from randomized controlled trials were unavailable, relapse rates were modeled using pharmacokinetic and pharmacodynamic evidence. These described blood plasma levels of aripiprazole as a function of AM and AL dose regimens and described the probability of relapse as a function of aripiprazole blood plasma levels. The analysis had a time horizon of 1 year and took the US healthcare payer perspective. The incremental cost per relapse avoided and the probability of cost effectiveness were calculated in deterministic and probabilistic analyses. Scenario analyses explored the model's main assumptions, and results were validated against external data and other cost-effectiveness analyses.

RESULTS

Monthly administration of AM 400 mg consistently yielded the lowest predicted number of relapses across deterministic, probabilistic, and scenario analyses. The costs of treatment and relapses were projected to be the lowest with a monthly administration of AL 441 mg. The incremental cost per relapse avoided with AM 400 mg ranged from AM 400 mg being dominant to $US83,300. From willingness-to-pay thresholds of $US30,000 per relapse avoided, the probability of cost effectiveness was highest for AM 400 mg. The validation showed alignment with external data.

CONCLUSION

The analysis highlighted the robustness of the novel framework based on pharmacokinetic and pharmacodynamic evidence and demonstrated an application in a postmarketing setting.

Reducing the Risk of Withdrawal Symptoms and Relapse Following Clozapine Discontinuation-Is It Feasible to Develop Evidence-Based Guidelines?

Clozapine is the only antipsychotic that is effective in treatment-resistant schizophrenia. However, in certain clinical situations, such as the emergence of serious adverse effects, it is necessary to discontinue clozapine. Stopping clozapine treatment poses a particular challenge due to the risk of psychotic relapse, as well as the development of withdrawal symptoms. Despite these challenges for the clinician, there is currently no formal guidance on how to safely to discontinue clozapine. We assessed the feasibility of developing evidence-based recommendations for (1) minimizing the risk of withdrawal symptoms, (2) managing withdrawal phenomena, and (3) commencing alternatives treatment when clozapine is discontinued. We then evaluated the recommendations against the Appraisal of Guidelines for Research and Evaluation (AGREE) II criteria. We produced 19 recommendations. The majority of these recommendation were evidence-based, although the strength of some recommendations was limited by a reliance of studies of medium to low quality. We discuss next steps in the refinement and validation of an evidence-based guideline for stopping clozapine and identify key outstanding questions.

Clinical Pharmacy in Psychiatry: Towards Promoting Clinical Expertise in Psychopharmacology

Although clinical pharmacy is a discipline that emerged in the 1960s, the question of precisely how pharmacists can play a role in therapeutic optimization remains unanswered. In the field of mental health, psychiatric pharmacists are increasingly involved in medication reconciliation and therapeutic patient education (or psychoeducation) to improve medication management and enhance medication adherence, respectively. However, psychiatric pharmacists must now assume a growing role in team-based models of care and engage in shared expertise in psychopharmacology in order to truly invest in therapeutic optimization of psychotropics. The increased skills in psychopharmacology and expertise in psychotherapeutic drug monitoring can contribute to future strengthening of the partnership between psychiatrists and psychiatric pharmacists. We propose a narrative review of the literature in order to show the relevance of a clinical pharmacist specializing in psychiatry. With this in mind, herein we will address: (i) briefly, the areas considered the basis of the deployment of clinical pharmacy in mental health, with medication reconciliation, therapeutic education of the patient, as well as the growing involvement of clinical pharmacists in the multidisciplinary reflection on pharmacotherapeutic decisions; (ii) in more depth, we present data concerning the use of therapeutic drug monitoring and shared expertise in psychopharmacology between psychiatric pharmacists and psychiatrists. These last two points are currently in full development in France through the deployment of Resource and Expertise Centers in PsychoPharmacology (CREPP in French).

Increased schizophrenia family history burden and reduced premorbid IQ in treatment-resistant schizophrenia: a Swedish National Register and Genomic Study

A high proportion of those with schizophrenia experience treatment non-response, placing them at higher risk for mortality and suicide attempts, compared to treatment responders. The clinical, social, and economic burden of treatment-resistant schizophrenia (TRS) are substantial. Previous genomic and epidemiological studies of TRS were often limited by sample size or lack of comprehensive genomic data. We aimed to systematically understand the clinical, demographic, and genomic correlates of TRS using epidemiological and genetic epidemiological modelling in a Swedish national population sample (n = 24,706) and then in a subgroup with common variant genetic risk scores, rare copy-number variant burden, and rare exonic burden (n = 4936). Population-based analyses identified increasing schizophrenia family history to be significantly associated with TRS (highest quartile of familial burden vs. lowest: adjusted odds ratio (aOR): 1.31, P = 4.8 × 10^-8). In males, a decrease of premorbid IQ of one standard deviation was significantly associated with greater risk of TRS (minimal aOR: 0.94, P = 0.002). In a subset of cases with extensive genomic data, we found no significant association between the genetic risk scores of four psychiatric disorders and two cognitive traits with TRS (schizophrenia genetic risk score: aOR = 1.07, P = 0.067). The association between copy number variant and rare variant burden measures and TRS did not reach the pre-defined statistical significance threshold (all P ≥ 0.005). In conclusion, direct measures of genomic risk were not associated with TRS; however, premorbid IQ in males and schizophrenia family history were significantly correlated with TRS and points to new insights into the architecture of TRS.

Effects of the combination of second-generation antipsychotics on serum concentrations of aripiprazole and dehydroaripiprazole in Chinese patients with schizophrenia

Background

Aripiprazole (ARI) is often prescribed alone or in combination with other second-generation antipsychotics (SGAs) to treat patients with schizophrenia. However, this may increase the potential clinical significance of drug–drug interactions. Therapeutic drug monitoring (TDM) is an important and fundamental tool both when administering ARI alone and in combination with other SGAs to monitor ARI pharmacokinetics, adjust the dosage and thereby achieve more effective and safer treatment.

Aims

This study retrospectively investigated the effects of four SGA comedications (clozapine, risperidone, quetiapine (QTP) and olanzapine) and other potential factors (sex, age and ARI dose) on the serum concentrations of ARI and dehydroaripiprazole (DARI) in Chinese patients with schizophrenia using TDM data.

Methods

High-performance liquid chromatography was used to test the serum concentrations of ARI, DARI and ARI+DARI. In addition, steady-state dose-adjusted serum concentrations (ie, concentration-to-dose ratios, C:D ratios) of ARI, DARI and ARI+DARI; sex; age; ARI dose and SGA comedication dose between 299 inpatients with schizophrenia who received ARI or SGA comedication were all collected and analysed. Spearman’s correlation and multiple linear regression analysis were used to evaluate bivariate associations between ARI dose and serum ARI and DARI concentrations and describe the effect of independent variables on serum ARI and DARI concentrations, respectively.

Results

There were significant differences in the C:D ratios of ARI (χ²=−3.21, p=0.001) and ARI+DARI (χ²=−2.50, p=0.01) between the ARI and SGA groups, as well as in the C:D ratios of ARI (χ²=−3.59, p<0.001) and ARI+DARI (χ²=−3.10, p=0.002) between the female patients in the two groups. Of the four SGAs, only QTP had significant effects on the C:D ratios of ARI (Z=−4.12, p<0.001) and ARI+DARI (Z=−3.62, p<0.001) when compared with the ARI group in the whole sample and on the C:D ratios of ARI, DARI and ARI+DARI (Z=−3.96, p<0.001; Z=−2.22, p=0.03; Z=−3.75, p<0.001, respectively) in women when compared with their counterparts in the ARI group.

Conclusion

Comedication with SGAs resulted in lower C:D ratios of ARI and ARI+DARI compared with ARI monotherapy, and comedication with QTP resulted in lower C:D ratios of ARI and ARI+DARI than ARI monotherapy. Despite this statistical significance of our findings, whether the presently observed effect has clinical significance requires exploration by further research. TDM and dosage regulation of ARI should be performed in Chinese inpatients with schizophrenia who are receiving SGA comedication (especially QTP) to maintain a safe and effective dose-adjusted serum concentration of ARI and DARI.

Dopamine and Glutamate in Antipsychotic-Responsive Compared With Antipsychotic-Nonresponsive Psychosis: A Multicenter Positron Emission Tomography and Magnetic Resonance Spectroscopy Study (STRATA)

The variability in the response to antipsychotic medication in schizophrenia may reflect between-patient differences in neurobiology. Recent cross-sectional neuroimaging studies suggest that a poorer therapeutic response is associated with relatively normal striatal dopamine synthesis capacity but elevated anterior cingulate cortex (ACC) glutamate levels. We sought to test whether these measures can differentiate patients with psychosis who are antipsychotic responsive from those who are antipsychotic nonresponsive in a multicenter cross-sectional study. 1H-magnetic resonance spectroscopy (1H-MRS) was used to measure glutamate levels (Glucorr) in the ACC and in the right striatum in 92 patients across 4 sites (48 responders [R] and 44 nonresponders [NR]). In 54 patients at 2 sites (25 R and 29 NR), we additionally acquired 3,4-dihydroxy-6-[18F]fluoro-l-phenylalanine (18F-DOPA) positron emission tomography (PET) to index striatal dopamine function (Kicer, min-1). The mean ACC Glucorr was higher in the NR than the R group after adjustment for age and sex (F1,80 = 4.27; P = .04). This was associated with an area under the curve for the group discrimination of 0.59. There were no group differences in striatal dopamine function or striatal Glucorr. The results provide partial further support for a role of ACC glutamate, but not striatal dopamine synthesis, in determining the nature of the response to antipsychotic medication. The low discriminative accuracy might be improved in groups with greater clinical separation or increased in future studies that focus on the antipsychotic response at an earlier stage of the disorder and integrate other candidate predictive biomarkers. Greater harmonization of multicenter PET and 1H-MRS may also improve sensitivity.

Rates of complete nonadherence among atypical antipsychotic drugs: A study using blood samples from 13,217 outpatients with psychotic disorders

BACKGROUND

Nonadherence to antipsychotics may cause relapse and hospitalizations in patients with psychotic disorders. The purpose was to quantify and compare the outpatient's nonadherence rates of atypical antipsychotics by objective detection in blood samples.

METHODS

Totally, 13,217 outpatients with therapeutic drug monitoring (TDM) data of atypical antipsychotics were included. An event of complete nonadherence was defined as an occurrence of undetectable level of a prescribed antipsychotic in the blood sample submitted for TDM. Patients with such an event(s) were defined as nonadherent of the respective drug treatment (outcome). The rates of nonadherence patients were compared between the drugs by logistic regression.

RESULTS

In the study population, 70.2% of the patients were prescribed doses compliant with a schizophrenia diagnosis. The mean olanzapine equivalent dose in the population was 13.4 mg (95% confidence interval (CI): 13.3, 13.6). The frequency of nonadherence patients, regardless of drug, was 3.7% (CI: 3.4-4.0). The nonadherence patient rate was lowest in clozapine-treated patients (2.2%; CI: 1.5-2.8), followed by aripiprazole (2.3%; 1.7-2.8), risperidone (2.4%; 1.6-3.0), quetiapine (2.8%; 2.3-3.2) and olanzapine (4.9%; 4.1-5.3). Users of olanzapine had significantly higher risk of complete nonadherence (Odds ratio: 1.9; CI: 1.6-2.3, p < 0.001) compared to patients treated with other antipsychotics as a group.

CONCLUSIONS

In this study, complete nonadherence of atypical antipsychotics, measured as undetectable blood level, was disclosed for ~5% of outpatients with psychotic disorders. The rate of complete nonadherence was significantly higher during olanzapine treatment compared to other atypical antipsychotics. Further studies should investigate if this reflects drug differences in tolerability or other causal relationships.

Prescription attitudes and practices regarding clozapine among Serbian psychiatrists: results of a nationwide survey

OBJECTIVE

Despite clozapine being the most effective treatment for treatment-resistant schizophrenia (TRS), a clear explanation as to why it is underutilized and why its initiation is delayed remains unclear. The first aim of the study was to conduct a nation-wide assessment of both the psychiatrists' attitudes of the obstacles for prescribing clozapine as well as their prescription practices. The second aim was to make recommendations, based on the results obtained, for improving the Serbian clozapine guidelines.

METHODS

A questionnaire was conducted consisting of two parts. One regarded the clinical characteristics of the psychiatrists, while the second contained questions about indications for clozapine initiation, clozapine prescribing tendencies, and barriers to clozapine use. The questionnaire was sent to 302 Serbian psychiatrists.

RESULTS

With 161 out of the 302 psychiatrists returning the questionnaires, the response rate was 53.3%. Nearly 60% of the psychiatrists treated 10 or more patients with clozapine, with TRS being the most common indication. Only four psychiatrists (2.5%) had no patients currently on clozapine. Psychiatrists indicated that their fear of agranulocytosis (68%) constituted the greatest obstacle for clozapine prescription, followed closely by weight gain (56%), and sedation (39%). Despite their fear of agranulocytosis, only 83.9% of the psychiatrists monitored leukocytes regularly.

CONCLUSION

In general, psychiatrists in Serbia seem to be confident in prescribing clozapine, even in the absence of clear monitoring guidelines and the possibility of therapeutic drug monitoring. In order to reduce obstacles for clozapine prescription, monitoring laxity, and an overreliance on personal experience, we recommend three modifications of the existing clozapine guideline.

Plasma Levels of Long-Acting Injectable Antipsychotics in Outpatient Care: A Retrospective Analysis

PURPOSE

Antipsychotic efficacy in schizophrenia depends on its availability in the body. Although therapeutic outcomes remain still far from satisfactory, therapeutic drug monitoring is not a common part of clinical practice during treatment with long-acting injectable antipsychotics (LAI AP). The real effectiveness of LAI AP is thus uncertain.

PATIENTS AND METHODS

We made a retrospective evaluation of plasma levels of LAI AP. Collection of blood samples was performed just before the drug application and one week later. Forty patients with a stabilized clinical condition and steady-state plasma levels were included.

RESULTS

In the observed cohort of patients, flupentixol decanoate (n = 23) was the most often used drug, followed by fluphenazine decanoate (n = 7), haloperidol decanoate (n = 5), paliperidone palmitate (n = 3), and risperidone microspheres (n = 2). Just 5 of 40 patients were treated with a monotherapy. In the period before the application, 60% of the patients did not reach the therapeutic reference range (TRR) and 20% of the patients had an undetectable plasma level. At the time of collection of the second blood samples performed after 7 days, 24% of the patients were under the TRR.

CONCLUSION

We have found a surprisingly high incidence of plasma levels under the TRR in patients treated with LAI AP. Notwithstanding individual variability in pharmacokinetics, it seems that LAI AP may be underdosed in usual clinical practice.

A Synthetic Literature Review on the Management of Emerging Treatment Resistance in First Episode Psychosis: Can We Move towards Precision Intervention and Individualised Care?

Treatment resistance is prevalent in early intervention in psychosis services, and causes a significant burden for the individual. A wide range of variables are shown to contribute to treatment resistance in first episode psychosis (FEP). Heterogeneity in illness course and the complex, multidimensional nature of the concept of recovery calls for an evidence base to better inform practice at an individual level. Current gold standard treatments, adopting a ‘one-size fits all’ approach, may not be addressing the needs of many individuals. This following review will provide an update and critical appraisal of current clinical practices and methodological approaches for understanding, identifying, and managing early treatment resistance in early psychosis. Potential new treatments along with new avenues for research will be discussed. Finally, we will discuss and critique the application and translation of machine learning approaches to aid progression in this area. The move towards ‘big data’ and machine learning holds some prospect for stratifying intervention-based subgroups of individuals. Moving forward, better recognition of early treatment resistance is needed, along with greater sophistication and precision in predicting outcomes, so that effective evidence-based treatments can be appropriately tailored to the individual. Understanding the antecedents and the early trajectory of one’s illness may also be key to understanding the factors that drive illness course.

Antipsychotic Treatment Failure: A Systematic Review on Risk Factors and Interventions for Treatment Adherence in Psychosis

Objective: Antipsychotic medication non-adherence has detrimental effects on patients' clinical outcome. It is unclear which risk factors affect adherence most and which interventions are effective at improving adherence to antipsychotic medication. The aim of this systematic review is to summarize evidence exploring risk factors of non-adherence to antipsychotic treatment and effectiveness of intervention to improve adherence in patients with psychotic spectrum disorders.

Methods: We conducted a systematic search in PubMed from 1994 to 2019 using a structured search strategy. Studies were quality assessed, and studies reporting on possible risk factors and intervention strategies were synthesized.

Results: We reviewed 26 studies on factors related to antipsychotic medication adherence and 17 studies on interventions to improve adherence in patients with psychosis spectrum disorders. Risk factors of non-adherence included younger age, poor illness insight, cannabis abuse, and the presence of severe positive symptoms. Antipsychotic medication adherence was associated with positive attitude toward medication of both patients and their family, family involvement, and illness insight. Somewhat consistent evidence was found for interventions involving family and technology-based interventions and strategies combining depot medication with psychoeducation. However, given the wide range of heterogeneous interventions and methodological limitations, findings must be interpreted with caution.

Conclusion: Despite much effort invested in the research area of antipsychotic medication adherence, the heterogeneity in study design and outcome, adding to confounding effects and possible biases, and methodological restraints complicate comparability of the results. Future research in this field should therefore be conducted on patient-tailored interventions, considering risk factors affecting the patient and implementing well-validated, standardized assessment methods. Accordingly, this systematic review seeks to facilitate endeavors improving adherence to antipsychotic treatment by identifying modifiable and non-modifiable risk factors, outlining effective intervention strategies, and proposing recommendations to enhance adherence strategies.

Antipsychotic medication versus psychological intervention versus a combination of both in adolescents with first-episode psychosis (MAPS): a multicentre, three-arm, randomised controlled pilot and feasibility study

BACKGROUND

Evidence for the effectiveness of treatments in early-onset psychosis is sparse. Current guidance for the treatment of early-onset psychosis is mostly extrapolated from trials in adult populations. The UK National Institute for Health and Care Excellence has recommended evaluation of the clinical effectiveness and cost-effectiveness of antipsychotic drugs versus psychological intervention (cognitive behavioural therapy [CBT] and family intervention) versus the combination of these treatments for early-onset psychosis. The aim of this study was to establish the feasibility of a randomised controlled trial of antipsychotic monotherapy, psychological intervention monotherapy, and antipsychotics plus psychological intervention in adolescents with first-episode psychosis.

METHODS

We did a multicentre pilot and feasibility trial according to a randomised, single-blind, three-arm, controlled design. We recruited participants from seven UK National Health Service Trust sites. Participants were aged 14-18 years; help-seeking; had presented with first-episode psychosis in the past year; were under the care of a psychiatrist; were showing current psychotic symptoms; and met ICD-10 criteria for schizophrenia, schizoaffective disorder, or delusional disorder, or met the entry criteria for an early intervention for psychosis service. Participants were assigned (1:1:1) to antipsychotics, psychological intervention (CBT with optional family intervention), or antipsychotics plus psychological intervention. Randomisation was via a web-based randomisation system, with permuted blocks of random size, stratified by centre and family contact. CBT incorporated up to 26 sessions over 6 months plus up to four booster sessions, and family intervention incorporated up to six sessions over 6 months. Choice and dose of antipsychotic were at the discretion of the treating consultant psychiatrist. Participants were followed up for a maximum of 12 months. The primary outcome was feasibility (ie, data on trial referral and recruitment, session attendance or medication adherence, retention, and treatment acceptability) and the proposed primary efficacy outcome was total score on the Positive and Negative Syndrome Scale (PANSS) at 6 months. Primary outcomes were analysed by intention to treat. Safety outcomes were reported according to as-treated status, for all patients who had received at least one session of CBT or family intervention, or at least one dose of antipsychotics. The study was prospectively registered with ISRCTN, ISRCTN80567433.

FINDINGS

Of 101 patients referred to the study, 61 patients (mean age 16·3 years [SD 1·3]) were recruited from April 10, 2017, to Oct 31, 2018, 18 of whom were randomly assigned to psychological intervention, 22 to antipsychotics, and 21 to antipsychotics plus psychological intervention. The trial recruitment rate was 68% of our target sample size of 90 participants. The study had a low referral to recruitment ratio (around 2:1), a high rate of retention (51 [84%] participants retained at the 6-month primary endpoint), a high rate of adherence to psychological intervention (defined as six or more sessions of CBT; in 32 [82%] of 39 participants in the monotherapy and combined groups), and a moderate rate of adherence to antipsychotic medication (defined as at least 6 consecutive weeks of exposure to antipsychotics; in 28 [65%] of 43 participants in the monotherapy and combined groups). Mean scores for PANSS total at the 6-month primary endpoint were 68·6 (SD 17·3) for antipsychotic monotherapy (6·2 points lower than at randomisation), 59·8 (13·7) for psychological intervention (13·1 points lower than at randomisation), and 62·0 (15·9) for antipsychotics plus psychological intervention (13·9 points lower than at randomisation). A good clinical response at 6 months (defined as ≥50% improvement in PANSS total score) was achieved in four (22%) of 18 patients receiving antipsychotic monotherapy, five (31%) of 16 receiving psychological intervention, and five (29%) of 17 receiving antipsychotics plus psychological intervention. In as-treated groups, serious adverse events occurred in eight [35%] of 23 patients in the combined group, two [13%] of 15 in the antipsychotics group, four [24%] of 17 in the psychological intervention group, and four [80%] of five who did not receive any treatment. No serious adverse events were considered to be related to participation in the trial.

INTERPRETATION

This trial is the first to show that a head-to-head clinical trial comparing psychological intervention, antipsychotics, and their combination is safe in young people with first-episode psychosis. However, the feasibility of a larger trial is unclear because of site-specific recruitment challenges, and amendments to trial design would be needed for an adequately powered clinical and cost-effectiveness trial that provides robust evidence.

FUNDING

National Institute for Health Research.

Undetectable or subtherapeutic serum levels of antipsychotic drugs preceding switch to clozapine

Adequate antipsychotic treatment intensity is required for defining treatment-resistant schizophrenia (TRS) and justifying clozapine treatment. We investigated the occurrence of undetectable or subtherapeutic serum levels of oral antipsychotics preceding switch to clozapine as an endpoint of TRS. For patients starting clozapine, 12-month retrospective reviews of antipsychotic serum concentration measurements were performed in a Norwegian therapeutic drug monitoring (TDM) database from 2005 to 2017. Undetectable levels in high-sensitive analytical assays defined ‘no drug use’, while levels <50% of the lower reference range defined ‘subtherapeutic use’. Similar data were collected for patients switching to long-acting injectable (LAI) antipsychotics, as a reference of ‘no or subtherapeutic drug use’. Nineteen of 353 patients initiating clozapine (5.4%) had a recent history of undetectable antipsychotic drug levels compared to 91 of 1048 (8.7%) initiating LAI. Another 19 patients starting clozapine (5.4%) had recent events of subtherapeutic levels. In conclusion, the present retrospective study may indicate that every 10th patient starting clozapine has a recent history of undetectable or subtherapeutic serum levels of oral antipsychotics. The clinical implications of the present study for the assessment of TRS should be investigated prospectively in further studies.

Personalized medicine begins with the phenotype: identifying antipsychotic response phenotypes in a first-episode psychosis cohort

AIMS

Here, we present a clustering strategy to identify phenotypes of antipsychotic (AP) response by using longitudinal data from patients presenting first-episode psychosis (FEP).

METHOD

One hundred and ninety FEP with complete data were selected from the PEPs project. The efficacy was assessed using total PANSS, and adverse effects using total UKU, during one-year follow-up. We used the Klm3D method to cluster longitudinal data.

RESULTS

We identified four clusters: cluster A, drug not toxic and beneficial; cluster B, drug beneficial but toxic; cluster C, drug neither toxic nor beneficial; and cluster D, drug toxic and not beneficial. These groups significantly differ in baseline demographics, clinical, and neuropsychological characteristics (PAS, total PANSS, DUP, insight, pIQ, age of onset, cocaine use and family history of mental illness).

CONCLUSIONS

The results presented here allow the identification of phenotypes of AP response that differ in well-known simple and classic clinical variables opening the door to clinical prediction and application of personalized medicine.

Using therapeutic drug monitoring to personalize clozapine dosing in Asians

This narrative review on clozapine blood levels or therapeutic drug monitoring (TDM) includes sections focused on drug clearance and TDM, personalized dosing with TDM, clinical applications of TDM in Asians, and areas needing further study. Asian patients need half the clozapine dose (D) used in the United States to get the same blood concentrations (C). The concentration-to-dose (C/D) ratio measures drug clearance. In the United States, the average clozapine patient usually needs from 300 to 600 mg/day to reach 350 ng/mL. US male smokers reach this therapeutic C with a D of 600 mg/day (C/D ratio of 0.60 = 600/350), whereas US female nonsmokers usually need a D of 300 mg/day (C/D ratio of 1.17 = 300/350). While in the United States, average CLO C/D ratios typically are 0.6-1.2 ng/mL per mg/day, in Asian populations they range from 1.20 in male smokers to 2.40 in female smokers, requiring Ds of 300 to 150 mg/day to obtain 350 ng/mL. Asian patients can become clozapine poor metabolizers (PMs), needing very low Ds (50-150 mg/day) to get therapeutic Cs, by taking inhibitors (fluvoxamine, oral contraceptives and valproic acid), due to obesity, or during inflammations with systemic effects. In 573 Asian patients from five samples, around 1% were PMs due to taking inhibitors, 1% due to inflammation, 1% due to obesity, and 7% were potential genetic PMs. The potential genetic PMs ranged between 3% and 13%, but this prevalence will have to be better established in future studies including genetic testing for possible CYP1A2 mutations, which may explain PM status.

Moderators and mediators of antipsychotic response in delusional disorder: Further steps are needed

Delusional disorder (DD) has been traditionally considered a relatively rare and treatment-resistant psychotic disorder. In the last decade, increasing attention has focused on therapeutic outcomes of individuals affected by this disorder. The aim of this paper is to provide a synthesis of the literature addressing two very important questions arising from DD research: (1) For which patients with DD do antipsychotic medications work best (the moderators of response); and (2) What variables best explain the relationship between such treatments and their effectiveness (the mediators of response). We searched PubMed and Google Scholar databases for English, German, French and Spanish language papers published since 2000. We also included a few classic earlier papers addressing this topic. Variables potentially moderating antipsychotic response in DD are gender, reproductive status, age, duration of illness, the presence of comorbidity (especially psychiatric comorbidity) and its treatment, brain structure, and genetics of neurochemical receptors and drug metabolizing enzymes. Antipsychotic and hormonal blood levels during treatment, as well as functional brain changes, are potential mediating variables. Some, but not all, patients with DD benefit from antipsychotic treatment. Understanding the circumstances under which treatment works best can serve to guide optimal management.

A Rational Use of Clozapine Based on Adverse Drug Reactions, Pharmacokinetics, and Clinical Pharmacopsychology

Using Richardson and Davidson's model and the sciences of pharmacokinetics and clinical pharmacopsychology, this article reviewed the: (1) poor life expectancy associated with treatment-resistant schizophrenia (TRS), which may be improved in patients who adhere to clozapine; (2) findings that clozapine is the best treatment for TRS (according to efficacy, effectiveness and well-being); and (3) potential for clozapine to cause vulnerabilities, including potentially lethal adverse drug reactions such as agranulocytosis, pneumonia, and myocarditis. Rational use requires: (1) modification of the clozapine package insert worldwide to include lower doses for Asians and to avoid the lethality associated with pneumonia, (2) the use of clozapine levels for personalizing dosing, and (3) the use of slow and personalized titration. This may make clozapine as safe as possible and contribute to increased life expectancy and well-being. In the absence of data on COVID-19 in clozapine patients, clozapine possibly impairs immunological mechanisms and may increase pneumonia risk in infected patients. Psychiatrists should call their clozapine patients and families and explain to them that if the patient develops fever or flu-like symptoms, the psychiatrist should be called and should consider halving the clozapine dose. If the patient is hospitalized with pneumonia, the treating physician needs to assess for symptoms of clozapine intoxication since halving the dose may not be enough for all patients; consider decreasing it to one-third or even stopping it. Once the signs of inflammation and fever have disappeared, the clozapine dose can be slowly increased to the prior dosage level.

Monitoring and improving antipsychotic adherence in outpatient forensic diversion programs

Outpatient diversion programs present an opportunity for severely mentally ill defendants to receive psychiatric treatment and have alleged offenses dismissed by the court. Moreover, the successful completion of pretrial diversion is associated with fewer post-program arrest and jail days. The target patient population for such programs is typically people with schizophrenia spectrum disorders, but the care of such patients in outpatient settings presents challenges for monitoring treatment fidelity, specifically antipsychotic adherence, as low adherence rates are associated with increased rates of recidivism. Presented here is a review of evidence-based strategies that must be employed to track antipsychotic adherence in outpatient diversion programs, including pill counts, use of long-acting injectable antipsychotics, and determination of plasma antipsychotic levels to assess adherence and the adequacy of antipsychotic treatment. Antipsychotic therapy remains the foundation of schizophrenia treatment, but only through the use of all available modalities can clinicians maximize the odds that schizophrenia patients in pretrial diversion maintain psychiatric stability and successfully complete mental health court mandates.

Indicated association between polygenic risk score and treatment-resistance in a naturalistic sample of patients with schizophrenia spectrum disorders

BACKGROUND

One third of people diagnosed with schizophrenia fail to respond adequately to antipsychotic medication, resulting in persisting disabling symptoms, higher rates of hospitalization and higher costs for society. In an effort to better understand the mechanisms behind resistance to antipsychotic treatment in schizophrenia, we investigated its potential relationship to the genetic architecture of the disorder.

METHODS

Patients diagnosed with a schizophrenia spectrum disorder (N = 321) were classified as either being treatment-resistant (N = 108) or non-treatment-resistant (N = 213) to antipsychotic medication using defined consensus criteria. A schizophrenia polygenic risk score based on genome-wide association studies (GWAS) was calculated for each patient and binary logistic regression was performed to investigate the association between polygenetic risk and treatment resistance. We adjusted for principal components, batch number, age and sex. Additional analyses were performed to investigate associations with demographic and clinical variables.

RESULTS

High levels of polygenic risk score for schizophrenia significantly predicted treatment resistance (p = 0.003). The positive predictive value of the model was 61.5% and the negative predictive value was 71.7%. The association was significant for one (p = 0.01) out of five tested SNP significance thresholds. Season of birth was able to predict treatment-resistance in the regression model (p = 0.05).

CONCLUSIONS

The study indicates that treatment-resistance to antipsychotic medication is associated with higher polygenetic risk of schizophrenia, suggesting a link between antipsychotics mechanism of action and the genetic underpinnings of the disorder.

Self-Report for Measuring and Predicting Medication Adherence: Experts' Experience in Predicting Adherence in Stable Psychiatric Outpatients and in Pharmacokinetics

THE PROBLEM

Poor adherence to appropriately prescribed medication is a global challenge for psychiatrists.

PRIOR STUDIES

Measuring adherence is complicated. In our recent three-country naturalistic study including more than 1000 patients and their adherence to multiple medication prescriptions at the same time, patients' self-report of adherence to each specific drug was the only practical option for measuring adherence. Systematic literature reviews provide inconsistent results for sociodemographic, clinical and medication variables as predictors of adherence to psychiatric drugs. Our studies over the last 10 years in relatively stable psychiatric outpatients have shown that some self-reported health beliefs had consistent, strong effects and a better predictive role. Three dimensions of these health beliefs are characteristics of the individual: 1) attitudes toward psychiatric medication such as pharmacophobia (fear of taking drugs or medicines), 2) health locus of control (the belief patients have about who or what agent determines the state of their health), 3) psychological reactance (an emotional reaction in direct contradiction to rules or regulations that threaten or suppress certain freedoms in behavior). They can be measured by the Patient Health Beliefs Questionnaire on Psychiatric Treatment. The attitude toward each specific medication can be measured by the necessity-concern framework and summarized as the presence or absence of skepticism about that drug. After 25 years conducting pharmacokinetic studies in psychiatric drugs, particularly antipsychotics, we have limited understanding of how to use blood levels to predict the effects of non-adherence or to establish it.

EXPERT OPINION ON FUTURE STUDIES

Future studies to predict adherence should include the inpatient setting and explore insight. Studying the pharmacokinetics associated with non-adherence in each psychiatric drug is a major challenge. Medication adherence is a complex and dynamic process changing over time in the same patient. Personalizing adherence using psychological or pharmacological variables are in their initial stages.

Predicting relapse with residual symptoms in schizophrenia: A secondary analysis of the PROACTIVE trial

INTRODUCTION

Little attention has been paid to the contribution of individual residual symptom to predict relapse in patients with schizophrenia receiving oral or long-acting injectable (LAI) antipsychotics.

METHOD

We used the data from the Preventing Relapse on Oral Antipsychotics Compared to Injectables - Evaluating Efficacy (PROACTIVE) study, in which 305 outpatients with schizophrenia were randomly allocated to either biweekly LAI-risperidone (LAI-R) or daily oral second-generation antipsychotics (SGA) and assessed for up to 30 months. Baseline individual symptoms that could predict subsequent relapse were identified, using a Cox proportional hazards model. Moreover, among those who relapsed during the study (n = 73), individual symptoms were compared between baseline and biweekly ratings 8 to 2 weeks before relapse, using the linear mixed model.

RESULTS

A greater score in grandiosity at baseline was significantly associated with subsequent relapse (adjusted HR = 1.24, p = 0.006). When the two treatment groups were separately analyzed, more severe grandiosity (adjusted HR = 1.43, p = 0.003) and less severe hallucinatory behavior (adjusted HR = 0.70, p = 0.013) at baseline were significantly associated with relapse in the oral SGA group, but none was identified in the LAI-R group. Emotional withdrawal was significantly worse 8 and 2 weeks before relapse compared to the baseline (p = 0.032 and p = 0.043, respectively).

DISCUSSION

More severe grandiosity and less hallucination may have led to more frequent relapses in patients with schizophrenia receiving oral antipsychotics, which was not a case in those receiving LAI-R. The exploratory analysis indicates an increase in emotional withdrawal before relapse may be a useful marker for earlier interventions to possibly avert relapse.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.